Significance Acute brain injuries are commonly encountered in the intensive care unit. Alterations in cerebrovascular physiology triggered by the initial insult can lead to neurological worsening, further brain injury, and poor outcomes. Robust methods for assessing cerebrovascular physiology continuously at the bedside are limited. Aim In this review, we aim to assess the potential of near-infrared spectroscopy (NIRS) as a bedside tool to monitor cerebrovascular physiology in critically ill patients with acute brain injury as well as those who are at high risk for developing brain injury. Approach We first review basic principles of cerebral blood flow regulation and how these are altered after brain injury. We then discuss the potential role for NIRS in different acute brain injuries. We pay specific attention to the potential for NIRS to (1) identify new brain injuries and clinical worsening, (2) non-invasively measure intracranial pressure (ICP) and cerebral autoregulation, and (3) identify optimal blood pressure (BP) targets that may improve patient outcomes. Results A growing body of work supports the use of NIRS in the care of brain injured patients. NIRS is routinely used during cardiac surgeries to identify acute neurologic events, and there is some evidence that treatment algorithms using cerebral oximetry may result in improved outcomes. In acute brain injury, NIRS can be used to measure autoregulation to identify an "optimum" BP where autoregulation status is best preserved. Finally, NIRS has been utilized to identify oximetry thresholds that correlate with poor outcome as well as identify new focal intracranial hemorrhages. Conclusions NIRS is emerging as a tool that can non-invasively measure brain function in critically ill patients. Future work will be aimed at technical refinements to improve diagnostic accuracy, as well as larger scale clinical trials that can establish a definitive impact on patient outcomes.

中文翻译：

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近红外光谱在神经重症监护中的应用。

意义 急性脑损伤在重症监护病房中很常见。最初的损伤引发的脑血管生理学变化可能导致神经功能恶化、进一步的脑损伤和不良结果。在床边连续评估脑血管生理学的稳健方法是有限的。目的在本次综述中，我们的目的是评估近红外光谱（NIRS）作为床边工具监测急性脑损伤危重患者以及脑损伤高危患者脑血管生理学的潜力。方法 我们首先回顾脑血流调节的基本原理以及脑损伤后这些原理如何改变。然后我们讨论 NIRS 在不同急性脑损伤中的潜在作用。我们特别关注 NIRS 的潜力：(1) 识别新的脑损伤和临床恶化，(2) 无创测量颅内压 (ICP) 和大脑自动调节，以及 (3) 确定最佳血压 (BP) 目标可以改善患者的治疗效果。结果 越来越多的工作支持使用 NIRS 来护理脑损伤患者。NIRS 通常在心脏手术期间用于识别急性神经系统事件，并且有一些证据表明使用脑血氧测定法的治疗算法可能会改善结果。在急性脑损伤中，NIRS 可用于测量自动调节，以确定最佳保持自动调节状态的“最佳”血压。最后，NIRS 已被用来识别与不良结果相关的血氧饱和度阈值以及识别新的局灶性颅内出血。结论 NIRS 正在成为一种可以无创测量危重患者脑功能的工具。未来的工作将致力于技术改进以提高诊断准确性，以及更大规模的临床试验，以对患者的治疗结果产生明确的影响。